#include <iostream>

using namespace std;

char grade(int);

int main(){
    int score;
    cout<<"请输入百分制成绩:";
    cin >> score;
    char ch = grade(score);
    cout << score <<"对应的等级为"<<ch << endl;
    return 0;
}

char grade(int n){
    char grade;
    if(n >= 90 && n< 100)grade = 'A';
    else if(n >=80)grade = 'B';
    else if(n >=70)grade = 'C';
    else if(n >=60)grade = 'D';
    else grade = 'E';
    return grade;
}
